[PATCH] iommu/sva: fix signedness bug in iommu_sva_alloc_pasid()

[Dan Carpenter <error27@gmail.com>]

The ida_alloc_range() function returns negative error codes on error.
On success it returns values in the min to max range (inclusive).  It
never returns more then INT_MAX even if "max" is higher.  It never
returns values in the 0 to (min - 1) range.

The bug is that "min" is an unsigned int so negative error codes will
be promoted to high positive values errors treated as success.

Fixes: 1a14bf0fc7ed ("iommu/sva: Use GFP_KERNEL for pasid allocation")
Signed-off-by: Dan Carpenter <error27@gmail.com>
---
 drivers/iommu/iommu-sva.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index c4ab3c457fbc..6e4f1ba1c148 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -33,8 +33,9 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t ma
 	}
 
 	ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL);
-	if (ret < min)
+	if (ret < 0)
 		goto out;
+
 	mm->pasid = ret;
 	ret = 0;
 out:
-- 
2.39.1